Medical implants are today frequently implanted into vertebrate animals, including humans, to replace anatomy and/or restore a function or appearance of the body.
Medical implants may be made of various materials depending on their intended use. Examples of materials include composite materials (mixed materials without chemical bond in between) and biodegradable materials that are absorbed by the body when they have fulfilled their tasks. Biodegradable materials are not only absorbed by the body but rather metabolized in the body and the end products completely secreted, excreted or exhaled from the body, e.g. as in the form of water and carbon dioxide. Silicon implants may be used to replace soft tissue parts. Stainless steel is a strong material often used when a high mechanical strength is necessary, such as for repairing fractures or replacing parts of joints. Polyethylene implants may be used for parts of joint replacement implants.
Also, many medical implants, such as e.g. dental implants, orthopedic implants and vascular stents, are metallic, i.e. they are made of a metal material. Examples of metal materials commonly utilized for constructing metallic medical implants are steel, titanium, zirconium, tantalum, niobium, hafnium and alloys thereof. In particular, titanium and titanium alloys have proved to be suitable to utilize for constructing medical implants. This is due to the fact that titanium is biocompatible, it has excellent corrosion resistance in body fluids, and it is light and strong.
Dental implants are utilized in dental restoration procedures in patients missing one or more teeth. A dental implant comprises a dental fixture, which is utilized as an artificial tooth root replacement. Thus, the dental fixture serves as a root for a new tooth. The dental fixture is typically screw-shaped, i.e. it has the threads of a screw. The implant is surgically implanted into the jawbone, where after the bone tissue grows around the fixture, optimally with the bone in direct contact with the implant surface. The process of integration of an implant into bone is called osseointegration when the bone grows directly in contact with the surface of the implanted fixture. By means of the osseointegration, a rigid, permanent installation of the implant is obtained.
Periodontal diseases are caused by bacteria and toxins in dental plaque, which is a sticky colourless film constantly forming on the surfaces of the teeth. These diseases are very common; it has been estimated that they affect as much as between 70-90% of the world population, and they are a major cause of tooth loss in people over 35 years of age. The most common forms of periodontal disease are gingivitis and periodontitis.
Periodontal disease is caused by bacterial deposits accumulating on tooth surfaces along the gingival margins and results in destruction of tooth-supporting tissues. The destruction of tooth-supporting tissues results in a deepening of the space (periodontal defect) between the root of the tooth and the gum tissue.
In patients with implants, a periodontitis-like condition may develop into a condition called peri-implantitis and is caused by the colonization of bacteria of the implants's surface. This condition is a new disease entity that has arrived with the more widespread use of dental implants. So far no predictable treatment strategy has been developed for healing of peri-implantitis, and no evidence based treatment regime is currently available. The infection may be caused by bacteria introduced during surgery or post-surgically by insufficient oral hygiene. Inflammation in the tissues surrounding the implant then causes loss of bone that ultimately may lead to loss of the implant. Patients with implants are also susceptible to developing a condition called peri-implant mucositis. This condition involves the presence of inflammation in the mucosa at an implant, but with no signs of loss of supporting bone in contrast to the observed bone loss in peri-implantitis patients.
Treatment of periodontal disease usually involves removing the bacterial deposits and dental calculus. This is commonly performed by manual scaling of the exposed root surface to remove bacterial deposits and dental calculus, including deposits in the gingival margin. However, full access for treating deeper periodontal pockets is difficult to achieve, resulting in remaining bacteria that may re-infect the tissue. Therefore, the treatment is often combined with surgical procedures to open the tooth pocket to expose the tooth. The roots are then mechanically freed from bacterial deposits and calculus but also granulation tissue and bacterial toxin removal. Alternative treatments also include debridement and rinsing of the subjacent affected tissue and local or systemic treatment with antibiotics and anti-inflammatory drugs.
Bacterial infections around implants are treated similarly with debridement of the exposed surfaces, and are of course not only a problem in the oral cavity but also in other parts of the body where implants are placed.
Further it is often advantageous or necessary to debride surgically exposed hard tissue surfaces. For example, debriding of surgically exposed hard tissue surfaces may be advantageous or necessary to perform before regenerative treatment, i.e. in order to prepare the hard tissue surfaces for regenerative treatment.
Rapid debridement treatment is important to ensure a better total treatment outcome. In addition, the total treatment outcome may also depend on the degree of damage caused onto the anatomical structure by the debridement tool used during the debridement procedure. Furthermore, the total treatment outcome may also depend on the amount of contaminating material residues that is left on the treated surface by the debridement tool. Contaminating material residues may trigger a foreign body response, toxic response or inflammation disproportionate to its beneficial effect.
In addition, the surface of implants and the surrounding tissue sometimes need cleaning after placement of the implant in the body. This is particularly important when an infection or contamination occurs. In these cases the surface of the ailing implant has to be cleaned from microbes and contaminants to stop the progression of the disease and potentially make re-integration of the implant possible. To maintain a stable treatment outcome and to prevent further disease progress, the implant surface must also be regularly cleaned both by the patient himself and by a dental professional in a clinic. If the implant surface is not sufficiently cleaned and maintained, it may lead to disease progression and eventually the loss of both the implant and the surrounding tissue, such as the jawbone.
Tools commonly used today for cleaning metallic implants are mostly designed for cleaning teeth and are relatively rigid and sharp in order to provide a thorough cleaning of the tooth root surfaces. Such cleaning tools may, for example, be made of stainless steel, titanium, hard metal alloys or hard polymers. These tools may not always be suitable for cleaning medical implants that often have a delicate surface structure that may be damaged when debrided with a rigid and sharp cleaning tool. Also, such cleaning tools may destroy the implant surface morphology and form surface damages in which bacteria may hide and adhere making surface decontamination difficult.
Also, the cleaning tools used for implant debridement today, leave contaminating material residues on the medical implant surface, or in the peri-implant tissue. Such material residues can cause a toxic reaction or a foreign body reaction and/or or other inflammatory reactions disproportionate to their beneficial effects, that may further exaggerate the peri-implant disease and thus potentially induce further loss of implant attachment.
In order to avoid the above-mentioned adverse events, a cleaning tool with a working part designed in a softer material may be utilized instead of the above-mentioned cleaning tools made of metals or hard plastics. The working part of said instruments may then be made of e.g. a plastic material, nylon or any other synthetic or natural fibers. One example of such a brush for cleaning a dental implant is disclosed in U.S. Pat. No. 6,345,406. However, the cleaning effect of such brushes on the medical implant surface is not as good as that of hard cleaning tools, i.e. it is easier to clean more efficiently and thoroughly by means of harder and sharper cleaning tools. In addition, in case such a brush is utilized for cleaning a medical implant surface, it is common that one or more soft bristles, or parts thereof, come loose from the tool and get stuck on the implant or in the surrounding tissue, e.g. mucosa, whereby toxic reactions or inflammation or infections often results.
Dental floss is a dental device for daily basis home care, dental and implant maintenance. Dental flosses or tapes are being used by patients to clean the spaces and remove plaque and deposits between the teeth or implants or between implants and teeth. The aim is to keep the gum or peri-implant mucosa margin clean and free of inflammation. Common floss materials are made of high tensile strength nondegradable organic polymers that rub off against the rough implant surface and thus inherently leaves significant amounts of contaminants locked into the surface structure. These contaminants are known to induce inflammatory responses that hampers the healing of the adjacent soft tissues and might actually provoke or exacerbate peri-implant disease.
As is evident from the above, the cleaning of implant surfaces and biological tissues are difficult and the methods available today are all suboptimal. In conclusion, there is a need for cleaning devices, which are strong enough to clean/debride well without damaging hard or soft tissue surfaces, and which does not leave contaminants on implants or in surrounding tissues that trigger toxic reactions, foreign body responses or other unfavorable inflammatory responses, and which may be utilized for relatively rapid cleaning of an implant or tissue surface.
Today, several implantable devices such as membranes, fixation plates, meshes, screws, tacks and sutures can be made of bioresorbable materials. However, so far no tools or instruments for medical use has been designed in biodegradable materials since there has been little interest for such devices, and the technology available has not been advanced enough to provide and manufacture biodegradable devices with the optimal combination of strength and degradability.
The object of the present invention is to overcome or at least mitigate some of the problems associated with the prior art.